One hundred years and many millions of flights after man first took to the sky, there remains one thing that can keep humans firmly on the ground - the weather.

Bouts of torrential rain and a lack of wind forced a delay to plans to recreate the first flight at the very time and place where Orville and Wilbur Wright succeeded in achieving their dream.

In poor weather, the replica aircraft flew like a piano

A replica of the 1903 Flyer stayed in its hangar as President George W Bush came and went and as tens of thousands of people huddled under their umbrellas hoping for the rain clouds to clear and the winds to strengthen.

But the plane that flew over the sand dunes of Kitty Hawk in North Carolina shortly after 1035 local time (1535 GMT) was not the wood and fabric bi-plane designed by the Wright Brothers, but something that seems futuristic even to us today - the B-2 Spirit Stealth Bomber on a commemorative fly-past.

The challenges posed by the elements were of course well known in 1903.

The brothers had been in Kitty Hawk since September hoping to test their powered flyer. But bad weather as well as technical problems meant it was not until mid-December that they finally got the chance to try their latest prototype.

Even then they had to be opportunists, taking advantage of breaks in the weather, just as the centennial organisers were forced to do, waiting and hoping for the right conditions to allow a modern audience a glimpse of what it might have been like to witness the first powered flight and the "12 seconds that changed the world".

'Genius'

But if the young bicycle shop proprietors would have recognised the problems, they would not have recognised the scenery.

FIRST FLIGHT

The Flyer weighed 341kg - including the pilot

It was 6.4m long with a 12.3m wingspan

The right wing was four inches longer than the left one to counter the engine weight

A Boeing 747 is 225ft long - 100ft longer than the first powered flight

Tom Crouch, senior curator for aeronautics at the National Air and Space Museum in Washington, told BBC News Online that sand dunes covered the area where the Wrights tested their gliders and later their powered aircraft.

On top of those dunes are now trees, memorial markers and grass, though that was churned to mud by the crowds and the rain.

It may look ordinary, the site was chosen for the wind not beauty, but it was here that history was made by what Mr Crouch called two ordinary men with "a quality of genius that set them apart".

"Before 1903, you heard people say 'If God had wanted us to fly, he would have given us wings'," he said. "They changed that."

'It hit a puddle'

President Bush came to the celebrations in his Marine One helicopter, a very modern flying machine, just yards from where Orville first reached for the sky in a powered airplane.

I was a little disappointed

Stephen Wright A great-grand-nephew of Orville and Wilbur

"There is something in the American character that allows us to look for a better way and is unimpressed when others say it cannot be done," the president said.

His patriotic speech was warmly welcomed by the damp crowd, but their real excitement began to show when the replica Flyer was pulled from its hangar.

A westerly wind picked up ever so slightly as helpers repeatedly cranked the propellers.

The crowd cheered as one when the engine finally caught and then it seemed to hold its breath shortly after 1230 as Flyer set off down the monorail which the Wrights used in lieu of a runway.

Willed by thousands, the nose of the aircraft rose and just maybe it cleared the ground for a split second before it veered right and into a puddle accompanied by groans of disappointment.

Changing the world

Perhaps the engine was not running quite right, perhaps there was not enough wind.

Stephen Wright said his famous relations faced their share of hitches

Stephen Wright, a great-grand-nephew of Orville and Wilbur, and his sister Amanda Wright Lane, told BBC News Online they were thrilled by the huge crowds who turned out to honour the men they knew through family stories as practical jokers before they knew them as American heroes.

They would have like to see the replica fly, but the reason for the day was what happened in 1903, not 2003.

"I was a little disappointed," Mr Wright said. "But there were more disappointments for the Wright Brothers 100 years ago. They were here for a couple of months trying to get this thing to fly and here we were given an exact hour to make it happen."

Fly-pasts from all manner of aircraft continued throughout the day, showing how far humans have come in improving flight - though seagulls soaring at will also demonstrated how far there is still to go.

After promises and even prayers, the Flyer was brought back out, but another attempt was not made.

There was disappointment certainly, but also perhaps even more admiration for Orville and Wilbur Wright who had no example to follow, but still took to the air.

And as the crowds left, children still played with tiny model planes, watching how the breeze caught their wings and maybe dreaming of how they could change the world as the Wright Brothers did.